Olivia Ludolf Posted September 11, 2012 Report Share Posted September 11, 2012 i'm doing maths studies and we doing arithmetic sequences but i don't get it what so ever so of the i do but i do not get this could someone help me:find k given the consecutive arithmitic terms k-1,2k+3,7-k Link to post Share on other sites More sharing options...
The Economist Posted September 11, 2012 Report Share Posted September 11, 2012 In arithmetic sequences you know that the second term doubled equals the sum of the first and the 3rd term. So, 4k+6=6 => k=0 Link to post Share on other sites More sharing options...
aangel Posted September 11, 2012 Report Share Posted September 11, 2012 So in an arithmetic sequence, each term differs (through addition and subtraction) from the previous by a common difference (D).so therefore in an arithmetic sequence- a, b, c, ..., etc.you can find d through,b-a = c-b = DTherefore,(2k+3)-(k-1)=(7-k)-(2k+3)2k+3-k+1=7-k-2k-3k+4=4-3k4k=0k=0Long way and you definitely wouldn't do this for every question, but I hope it helps you understand. 1 Link to post Share on other sites More sharing options...
The Economist Posted September 11, 2012 Report Share Posted September 11, 2012 Automatic generated messageThis topic has been closed by a moderator.Reason: Question answered.If you disagree with this action, please report this post and a moderator or administrator will reconsider it.Kind regards,IB Survival Staff Link to post Share on other sites More sharing options...
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